This invention concerns so-called "air bag" systems in which an inflatable cushion is stored within a compartment or receptacle in an auto or truck vehicle passenger compartment behind an interior trim piece. When a sensor system detects the onset of a serious crash, the system is triggered, causing gas generators to be activated and the cushion, commonly called "air bag", to be inflated. When inflated, each air bag deploys into a proper position within the passenger compartment to protect the passenger or driver against impact with the interior structure of the vehicle.
The air bag is stored behind an interior trim piece such as the steering wheel cover or a section of the instrument panel, and deploys through an opening provided at the instant of system activation, typically involving a hinged door pushed open by the inflating air bag. U.S. Pat. Nos. 5,083,393 and 4,991,870 describe such installations.
Providing such an opening is a difficult design problem since the air bag must be securely protected against tampering, yet very reliably operable to allow the air bag to deploy within a few milliseconds after the system is activated.
The deployment opening in the associated trim pieces should be invisible so as to not suggest the presence of the stored air bag, as any indication of its presence makes some individuals uneasy, and invites tampering by others. Contrariwise, typical arrangements for providing a deployment opening heretofore employed have delineated or at least suggested the presence of the air bag.
Such arrangements proposed in the past have also often involved extra components and complex assemblies of trim parts such as the instrument panel, increasing costs substantially and reducing reliability.